– click for General Verification Guidelines | – click for Specific Verification Guidelines 
– Rare / Uncommon / Scarce
Birch Conch
– care required in the identification process, as confusion with similar species is likely – quality photographs required. Confusion Species: Brevicornutia pallidana (Sheep’s-bit Straw)
ID pointers: The forewing apex is whitish heavily mixed with yellow ochre, especially towards the cilia and grey tones through the basal area extending to the costa. A darker greyish central area cross-band
Distribution: (Last record: 23 March 2025 at Belper ) – Uncommon few records – Harrison & Sterling – 6 accounts from 1905 – 1981 & 1947-56 from Taxal. DaNES 3 records 2003 & 2 in 2009 from Belper & Ilkeston – iRecord 6 recent records between 2019 – 2024.
*** Last updated on 2 October 2025 by RP ***
Last Recorded Year: 2024
Last Recorded By – Dave Evans
Last Recorded General Area – Belper
Selected Images:
Belper (2021 & 2024) Dave Evans©
Image Gallery
No gallery images found for this moth.
Distribution Map for Thyraylia nana
Found 11 records
↳ 2 from After 2025
↳ 4 from 2020 - 2024
↳ 5 from Before 2020
↳ 2 from After 2025
↳ 4 from 2020 - 2024
↳ 5 from Before 2020
If the Map Layers function fails, just refresh the page and it should be OK after. Use the +- zoom on the top left, or on a tablet, use two fingers to zoom. Remember, the last layer you ticked is the one which displays the popup information - they sit on top of each other - de-select then re-select, to see the popup values.
Bedrock Geology ** indirectly affects moth distribution by influencing the type of habitat and food plants available in an area. In turn, this may affect the types of moths that can thrive, or where they can most likely be found.
NBN Atlas UK Distribution for – Thyraylia nana
⚠️ Please wait for the map to load fully – do not click the link shown.
Note – the NBN Atlas datasets are listed in the map below and vary in their currency (uptodateness) – however,
the map does give a general indication of the moth's distribution across the UK.
Monthly Records By Year:
Thyraylia nana
( data includes both Larvae and Adult Stages )
Monthly Counts By Year: Thyraylia nana
( data is based on 'Adult' stage records only. )
First/Last Recorded Dates: Thyraylia nana
Adult-only & Anything [Larvae, Pupae, Adult, Mines]
Shading shows moth presence between dates
Click the colour discs below to Select/De-select as Required
Recordings By Year: Thyraylia nana
( All data includes both Larvae and Adult Stages )
Annual Growth Rate (AGR): Thyraylia nana
AGR: 0% | Total % Change: 0%
CUSUM Analysis: Thyraylia nana
About this chart: CUSUM (Cumulative Sum) charts track long-term trends in moth populations [ filtered by 'Adult' and 'Mine' life stages ] by showing whether each year’s counts are above or below the historical average. Even small shifts build up over time, making trends of growth, stability, or decline easier to see. CUSUM highlights trend-consistency — asking: “Across the years, have moth counts mostly stayed above or below average?”
The data sample has 19 gap year/s here (zero records) between 2000 and 2025. The moth may have been present in those gap years, but no data was available. Too many year-gaps may exaggerate or skew the chart.
Counts for the current year (2025) are pro-rated based on data available up to month 8 (August) to provide a full-year equivalent.
ⓘ
Purple line rises = years better than average; falls = years worse than average.
Peak (best year)
Trough (worst year)
Growth periods
Decline periods
Population peaked around 2025, reaching above average levels. The lowest population point occurred near 2024, showing a significant decline.
What the Y-axis "Cumulative Deviation" means: Cumulative Deviation shows the running total of how each year’s moth population count differs from the long-term average. i
Hectad (10kmx10km) Coverage: Thyraylia nana
( data includes both Larvae and Adult Stages )
Flight Periods – Indicative –vs– Recorded Data
Thyraylia nana
Thyraylia nana
( data includes Adult Stage only )
Flight Period chart – the grey hatched area above, which can cross one or more months, pictorially represents the best guess we have for this moth's flight periods [month/s]. The coloured lines represent the actual months seen in flight, from site observation records received between 2020-2025.
Records Behind the Map and Charts - Thyraylia nana – 11 records available
Listed by Year - descending - scroll across to see all table columns
| Site Name | Tetrad | Date | Count | Stage | Source |
|---|---|---|---|---|---|
| Spring Wood, Calke | SK32W | 25/05/2025 | 1 | adult | vc57_irecords_extract |
| Longdendale, Torside grassland and willow carr | SK09U | 12/05/2025 | 1 | adult | vc57_irecords_extract |
| Belper | SK34N | 29/05/2024 | 1 | adult | vc57_irecords_extract |
| Woodland Ave | SK43R | 08/07/2021 | 1 | adult | vc57_irecords_extract |
| Woodland Ave | SK43R | 26/06/2021 | 1 | adult | vc57_irecords_extract |
| Belper | SK34U | 17/06/2021 | 1 | adult | vc57_irecords_extract |
| Birch Vale | SK08I | 31/05/2019 | 1 | adult | vc57_irecords_extract |
| Bristol Rd,Ilkeston | SK44R | 28/05/2009 | 1 | Adult | vc57_danes_bc_data |
| Wheeldon Av,Belper | SK34N | 24/05/2009 | 1 | Adult | vc57_danes_bc_data |
| Main Street, Kings Newton | SK32Y | 09/06/2007 | 1 | Adult | vc57_irecords_extract |
| Wood Lane,Newhall,Swadlincote | SK22V | 18/08/2003 | 1 | Adult | vc57_danes_bc_data |